How to assign global variables as parameters inside functions?

Question

I want to directly use a global variable as a parameter of a function, and then assign a value to the parameter inside the function, instead of directly assigning a value to the global variable inside the function, so that it will not be hard-coded, but the test cannot assign a value.

s = 1;
a(s);
function a(m){
    e = m;
    b(e);
    function b(f){
        f = 2;
    }
}
alert(s);

The result is that s is still equal to 1. I know that s can be assigned a value directly in a function, but wouldn’t that be too hard to write? How can I assign a value of 2 to s in this way? It is convenient to pass different global variables for use later.

Answer 1

JS object scope, take a closer look~

Answer 2

You don’t understand the connotation of function parameter passing: value passing, which means that S just gives 1 to function A and does not participate in it. In layman's terms: If you copy an S to a function, no matter how you operate it, it will not affect S itself.